反应详情

2,6-Dichloropurine (378 mg, 2.0 mmol) was dissolved in dimethylsulfoxide (10 mL), and dry potassium carbonate (345 mg, 2.5 mmol), and iodoethane (312 mg, 2.0 mmol) added. The mixture was stirred at room temperature for 16 hours, then the mixture was diluted with ice, acetic acid was added to adjust the pH to 5, and the solution was extracted with ethyl acetate. The combined extracts were washed with water, dried over sodium sulfate, filtered, and the filtrate evaporated in vacuo. The residue was purified by flash chromatography, eluting initially with cyclohexane-EtOAc (75:25) to give 2,6-dichloro-9-ethylpurine (280 mg, 65%), a compound of formula (2). mp 100–103° C.; UV λmax (MeOH) 214 nm (ε 22900), 274 (ε 9500), (pH 1) 213 nm (ε 22800), 273 (ε 9500), (pH 12) 214 nm (ε 17900), 260 (ε 7800), 266 (ε 8100); 1H NMR (Me2SO-d6) δ 1.45 (t, 3H, J=7.2 Hz, CH2CH3), 4.28 (q, 2H, J=7.2 Hz, CH2CH3), 8.77 (s, 1H, H-8). Anal. (C7H6Cl2N4) C, H, N.

1. additionwas added
2. extractionthe solution was extracted with ethyl acetate
3. washThe combined extracts were washed with water
4. dry with materialdried over sodium sulfate
5. filtrationfiltered
6. customthe filtrate evaporated in vacuo
7. customThe residue was purified by flash chromatography
8. washeluting initially with cyclohexane-EtOAc (75:25)